As we know that GPON uses the optical wave length range from 1480 - 1500 nm for upstream with the optical center wave length is 1490 nm, and the optical length range from 1260-1360 nm for downstream with the optical center wave length is 1310 nm. Actually in GPON transceiver uses two GPON SFP types, those are SFP class B+ and SFP class C+, so what are similar and different features between them? To understand more deeply about GOPN SFP features, we will go to investigate important specifications of them.
GPON small form factor pluggable (SFP) is a terminal optical interface, it designed under the optical module with SC receptacle, compliant with ITU-T G.984.2 and used on OLT transceivers or ONU transceivers to transmit and receive the data between service provider and customer. GPON SFP module allows performing hot-plug without affecting the operating service.
Depend on transmitted power, received sensitivity and splitting ratios (large or small splitting ratio)in GPON network, GPON SFP types will be selected to ensure the quality of service and save the cost, so the transmitted power and received sensitivity of SFP base on criteria bellow.
- SFP class B+ for OLT transceiver: Tx power from 1.5 ~5dB, Rx sensitivity around -28dB
- SFP class B+ for ONU transceiver: Tx power from 0.5 ~ 5dB, Rx sensitivity around -27dB
- SFP class C+ for OLT transceiver: Tx power from 3 ~7dB, Rx sensitivity around -32dB
- SFP class C+ for ONU: Tx power from 0.5 ~ 5dB, Rx sensitivity around -30dB
|Features||GPON SFP class B+||GPON SFP class C+|
|Compliant with||ITU-T G.984.2||ITU-T G.984.2|
|Port rate (upstream/downstream)||1.244/2.488 (Gbps)||1.244/2.488 (Gbps)|
|Centre wave length (Tx)||1490 nm||1490 nm|
|Centre wave length (Rx)||1310 nm||1310 nm|
|Average output power||1.5 to 5 dBm||3 to 7 dBm|
|Extinction ratio||10 dB||8.2 dB|
|Optical output power Tx off||-40 dBm||-40 dBm|
|Sensitivity||-28 dBm||-32 dBm|
|Receiver overload||-8 dBm||-12 dBm|
|Optical fiber type||Single mode||Single mode|